1. Field of The Invention
The present invention relates to a card connector, and particularly to an improved switch structure for a smart card connector.
2. The Prior Art
Following the development of electronic technology, a variety of electronic cards such as smart cards and SIM (Subscriber Identity Module) cards are becoming increasingly popular. A variety of connectors have been designed to electrically connect such cards to mainframes, such as those disclosed in U.S. Pat. Nos. 4,735,578, 4,752,234, 4,900,272, 4,900,273, 5,013,255, 5,334,034, 5,370,544, and 5,380,997, each of which is equipped with a switch for detecting insertion of an electronic card thereinto.
FIGS. 5 and 6 show a card connector 2 in accordance with U.S. Pat. No. 5,013,255 which includes a dielectric housing 20 defining two contact receiving regions 201, a slot 203 for receiving an electrical card (not shown) into the connector 2, and a stop wall 202 which engages with the inserted card when it reaches its final inserted position, a number of reading contacts 21 fixedly received in the regions 201, each reading contact 21 having a curved contact portion 212 for electrically connecting with the inserted electrical card and a tail portion 214 for being soldered to a printed circuit board (PCB, not shown), and a switch 22 consisting of a first switch member 220 and a second switch member 23 which electrically connect with each other when no card is inserted into the connector 2, as shown in FIG. 5. The first and second switch members 220, 23 have tails 222, 232 for being soldered to the PCB, respectively. When an electrical card is inserted into the connector 2 and reaches the final inserted position, it pushes a ridge 223 of the first switch member 220 rearwards causing it to disengage from the second switch member 23, as shown in phantom lines in FIG. 6, whereby an insertion of a card into the connector 2 is detected. When the card is withdrawn from the connector 2, the first switch member 220 returns to its original position due to its resiliency to re-engage with the second switch member 23 whereby a card is not detected in the connector 2.
Since the first switch member 220 returns to its original position due to its resiliency and the connector 2 may be used extensively, after a period of use the first switch member 220 may be fatigued so that it can no longer return to its original position to positively engage with the second switch member 23. When this happens, the connector 2 does not work properly.
Hence, an improved card connector is needed to eliminate the above mentioned defects of current card connectors.